5 ms·

Putting it here, as it seems relevant. Veritasium: Parallel World Probably Exist: Here's Why https://www.youtube.com/watch?v=kTXTPe3wahc https://www.youtube.c

Putting it here, as it seems relevant. Veritasium: Parallel World Probably Exist: Here's Why https://www.youtube.com/watch?v=kTXTPe3wahc https://www.youtube.com/watch?v=kTXTPe3wahc

light_hue_1 3y ago
The word "probably" there is completely meaningless. There are many interpretations of QM and there is no compelling reason to choose one over the others. In particular the many worlds interpretation makes no testable predictions, it's just a story. There's absolutely nothing "elegant" about it. There's no math, no experiment, no explanation. A story like you read in some religious text or science fiction novel. It has nothing more going for it than that. Practically, the most "likely" situation, if you want to define likely as what most researchers think and how they behave, is that most people are fans of "shut up and calculate". QM is what it is. That's it. We don't need crazy interpretations, particularly ones that don't contribute anything to our understanding.
- semi-extrinsic 3y ago
  This. So much this. And also https://xkcd.com/1240/ https://xkcd.com/1240/
- goatlover 3y ago
  Shut and calculate is putting your head in the sand and avoiding that physics should be telling us what the world is. You’re wrong about MWI in that it’s a more elegant interpretation because it adds nothing extra to the wave equation and treats the universe as fundamentally quantum with no arbitrary dividing lines for classically scaled objects.
  - light_hue_1 3y ago
    > Shut and calculate is putting your head in the sand and avoiding that physics should be telling us what the world is. It's how physics is done. PhD students don't sit in physics departments getting ideas from their interpretation of QM. The interpretations people have are so meaningless and useless they never appear in physics publications. You don't like it, but it's what physics is. > You’re wrong about MWI in that it’s a more elegant interpretation because it adds nothing extra to the wave equation and treats the universe as fundamentally quantum with no arbitrary dividing lines for classically scaled objects. That's the thing about most QM interpretations, and in particular the many worlds interpretation, and why they aren't science just stories: you're right, they add nothing. So they are untestable! What does untestable mean? It means that they make no predictions about our world at all. They are stories. Their impact on physics or the universe we live in is the same as that of Winnie-the-Pooh. They're a waste of time. > avoiding that physics should be telling us what the world is. What can I say to "should"? I can only report what physics is in the real world. That's like saying, biologists "should" be working on building Jurassic Park because that's what you feel is the goal of the field. It's not. That's not what they do.
    - goatlover 3y ago
      > It's how physics is done. PhD students don't sit in physics departments getting ideas from their interpretation of QM. The interpretations people have are so meaningless and useless they never appear in physics publications. They do if they're going into foundations of physics. There's a sociological problem where the Copenhagen interpretation won out in the past and resulted in the shut up and calculate orthodoxy in teaching physics. But there are physicists like Sean Carol who think that's a historical mistake and based on failing to think about QM correctly. https://www.preposterousuniverse.com/podcast/2023/06/26/241-tim-maudlin-on-locality-hidden-variables-and-quantum-foundations/ https://www.preposterousuniverse.com/podcast/2023/06/26/241-... > That's the thing about most QM interpretations, and in particular the many worlds interpretation, and why they aren't science just stories: you're right, they add nothing. So they are untestable! Some make testable predictions like the collapse theories. For the others, it's more about the proper way to understanding what the mathematical formalism and experimental results are telling us about the world, and how we can use that to advance future physics. > What can I say to "should"? I can only report what physics is in the real world. And there have always been physicists like Einstein, Everett, Bohm and Bell who pushed back.
      - light_hue_1 3y ago
        > They do if they're going into foundations of physics People don't do PhDs on this topic because it's not productive. Famous/bored/tenured/rich people pitch in arguments for fun. Anyway, the vast majority of work in foundations of physics has nothing to do with these interpretations https://link.springer.com/journal/10701/volumes-and-issues https://link.springer.com/journal/10701/volumes-and-issues This is a niche inside a niche in a mostly irrelevant field. No advance in physics has ever been made based on QM interpretations. No Nobel has ever been won. No phenomena have ever been discovered this way. It's just not what people work on and it's not how physics is done. You're determined that your view of the world is right, and that of actual working scientists is somehow blind orthodoxy that's missing the point. There's nothing I can say to fix that. It's like arguing with an antivaxer. You think you know more than the people doing the work. Bye stranger! But.. it's worth considering that here and elsewhere in life your probably don't know better.
  - tsimionescu 3y ago
    > You’re wrong about MWI in that it’s a more elegant interpretation because it adds nothing extra to the wave equation and treats the universe as fundamentally quantum with no arbitrary dividing lines for classically scaled objects. That's how it's often presented, but this is wrong. In fact, it does add something to the theory, and that's a measure of how many "worlds" there are after a quantum measurement, which helps translate the wave function values into testable probabilities (the Born rule). In the CI, after a measurement, the wave function collapses into a single value, leaving the single world in a single classical state, with some probability that's equal to the modulus of the wave function amplitude of that state (or is there some squaring involved as well?). In the MWI, after a measurement, different versions of the observer observe different states, and the number of versions of the observer observing each state corresponds to the modulus of the wave function amplitude of that state. Then, via simple probability, we can say this count corresponds to the actual probability that any one version of the observer will notice one particular state, even though in the actual multiverse all of the states actually happen. As you can see, the two interpretations require the same amount of extra postulates above and beyond the wave function itself. Also, the MWI has to somehow define a formal notion of an observer/a classical world, which runs into questions of scale just as much as the measurement postulate of CI.
    - Joker_vD 3y ago
      > the MWI has to somehow define a formal notion of an observer/a classical world Yes: in MWI, those things don't exist. The world is quantum all the way up and all the way down, observers are simply (other) quantum system that get to interact with the quantum system under the consideration. An observation, then, is simply an interaction between two quantum systems and follows all the usual rules so instead of the wave-function collapse leaving you with the observed system in pure state X and the observer is in pure state Y, you get a huge superposition of "the observed system in pure state Xi, the observer is in pure state Yi" states in the end. Those substates, in a sense, are multiple worlds.
      - tsimionescu 3y ago
        You're missing the point I was highlighting. Quantum mechanics makes very specific, very precise predictions about the probabilities of an observer seeing any of those states, which we have confirmed are correct to extraordinary precision. The problem is explaining what is the relationship between these observed probabilities and the wave function amplitudes. If we say that all possible quantum states are realized in the universal wave function, we the need to explain why different states have different probabilities to an observer. The only way to do that in the deterministic world of MWI is to add a new postulate: one that says that for any state Xi, there are N observers in state Yi, where N = |psi(Xi)|, so that we can compute regular frequentist probabilities of an observer seeing a particular state over the amount of observers. This is perfectly reasonable, but it is just as much an extra postulate as the measurement postulate.
- tauwauwau 3y ago
  I watched it a long time ago. I just put it here because it presents the idea visually, not because I support or even understand it :)
- consilient 3y ago
  > In particular the many worlds interpretation makes no testable predictions, it's just a story. Yes, that's what "interpretation" means. If it made predictions that distinguished it from other interpretations, it would be a competing theory to quantum mechanics - and so far all such attempts have failed.
- TillE 3y ago
  The "popular science" takes on QM have generally been an enormous failure, focused on irrelevant fluff like this. I mean, I get it, it's a subject that you can't seriously understand without a degree in physics or chemistry. I had plenty of trouble with the math even at the undergrad level. But surely there's more interesting stories to tell of eg particle accelerator research, rather than fantasies.
  - mrguyorama 3y ago
    More importantly, if you don't have 4 years worth of college math, quantum mechanics is EXTREMELY BORING from a layman's perspective. It's a bunch of extremely dense and specific math with very loaded concepts and terms and has no meaning to anyone who doesn't have a strong understanding of classical physics. "If you make a blackbody radiator nearly absolute zero, it should emit insanely high energy radiation based on our current empirical equations for radiated energy. This can only be fixed if energy can only be radiated in discrete sized packets, including a minimum size of packet" "Whats a black body radiator?" People don't understand quantum physics, its ramifications, or why that's interesting to physicists because people can't even be assed to do simple mental math at a grocery store to get themselves good deals before they go back to their algebra teacher and complain that they will never use math in real life

Putting it here, as it seems relevant. Veritasium: Parallel World Probably Exist: Here's Why https://www.youtube.com/watch?v=kTXTPe3wahc https://www.youtube.com/watch?v=kTXTPe3wahc

light_hue_1 3y ago

The word "probably" there is completely meaningless. There are many interpretations of QM and there is no compelling reason to choose one over the others. In particular the many worlds interpretation makes no testable predictions, it's just a story. There's absolutely nothing "elegant" about it. There's no math, no experiment, no explanation. A story like you read in some religious text or science fiction novel. It has nothing more going for it than that. Practically, the most "likely" situation, if you want to define likely as what most researchers think and how they behave, is that most people are fans of "shut up and calculate". QM is what it is. That's it. We don't need crazy interpretations, particularly ones that don't contribute anything to our understanding.

semi-extrinsic 3y ago
This. So much this. And also https://xkcd.com/1240/ https://xkcd.com/1240/
goatlover 3y ago
Shut and calculate is putting your head in the sand and avoiding that physics should be telling us what the world is. You’re wrong about MWI in that it’s a more elegant interpretation because it adds nothing extra to the wave equation and treats the universe as fundamentally quantum with no arbitrary dividing lines for classically scaled objects.
- light_hue_1 3y ago
  > Shut and calculate is putting your head in the sand and avoiding that physics should be telling us what the world is. It's how physics is done. PhD students don't sit in physics departments getting ideas from their interpretation of QM. The interpretations people have are so meaningless and useless they never appear in physics publications. You don't like it, but it's what physics is. > You’re wrong about MWI in that it’s a more elegant interpretation because it adds nothing extra to the wave equation and treats the universe as fundamentally quantum with no arbitrary dividing lines for classically scaled objects. That's the thing about most QM interpretations, and in particular the many worlds interpretation, and why they aren't science just stories: you're right, they add nothing. So they are untestable! What does untestable mean? It means that they make no predictions about our world at all. They are stories. Their impact on physics or the universe we live in is the same as that of Winnie-the-Pooh. They're a waste of time. > avoiding that physics should be telling us what the world is. What can I say to "should"? I can only report what physics is in the real world. That's like saying, biologists "should" be working on building Jurassic Park because that's what you feel is the goal of the field. It's not. That's not what they do.
  - goatlover 3y ago
    > It's how physics is done. PhD students don't sit in physics departments getting ideas from their interpretation of QM. The interpretations people have are so meaningless and useless they never appear in physics publications. They do if they're going into foundations of physics. There's a sociological problem where the Copenhagen interpretation won out in the past and resulted in the shut up and calculate orthodoxy in teaching physics. But there are physicists like Sean Carol who think that's a historical mistake and based on failing to think about QM correctly. https://www.preposterousuniverse.com/podcast/2023/06/26/241-tim-maudlin-on-locality-hidden-variables-and-quantum-foundations/ https://www.preposterousuniverse.com/podcast/2023/06/26/241-... > That's the thing about most QM interpretations, and in particular the many worlds interpretation, and why they aren't science just stories: you're right, they add nothing. So they are untestable! Some make testable predictions like the collapse theories. For the others, it's more about the proper way to understanding what the mathematical formalism and experimental results are telling us about the world, and how we can use that to advance future physics. > What can I say to "should"? I can only report what physics is in the real world. And there have always been physicists like Einstein, Everett, Bohm and Bell who pushed back.
    - light_hue_1 3y ago
      > They do if they're going into foundations of physics People don't do PhDs on this topic because it's not productive. Famous/bored/tenured/rich people pitch in arguments for fun. Anyway, the vast majority of work in foundations of physics has nothing to do with these interpretations https://link.springer.com/journal/10701/volumes-and-issues https://link.springer.com/journal/10701/volumes-and-issues This is a niche inside a niche in a mostly irrelevant field. No advance in physics has ever been made based on QM interpretations. No Nobel has ever been won. No phenomena have ever been discovered this way. It's just not what people work on and it's not how physics is done. You're determined that your view of the world is right, and that of actual working scientists is somehow blind orthodoxy that's missing the point. There's nothing I can say to fix that. It's like arguing with an antivaxer. You think you know more than the people doing the work. Bye stranger! But.. it's worth considering that here and elsewhere in life your probably don't know better.
- tsimionescu 3y ago
  > You’re wrong about MWI in that it’s a more elegant interpretation because it adds nothing extra to the wave equation and treats the universe as fundamentally quantum with no arbitrary dividing lines for classically scaled objects. That's how it's often presented, but this is wrong. In fact, it does add something to the theory, and that's a measure of how many "worlds" there are after a quantum measurement, which helps translate the wave function values into testable probabilities (the Born rule). In the CI, after a measurement, the wave function collapses into a single value, leaving the single world in a single classical state, with some probability that's equal to the modulus of the wave function amplitude of that state (or is there some squaring involved as well?). In the MWI, after a measurement, different versions of the observer observe different states, and the number of versions of the observer observing each state corresponds to the modulus of the wave function amplitude of that state. Then, via simple probability, we can say this count corresponds to the actual probability that any one version of the observer will notice one particular state, even though in the actual multiverse all of the states actually happen. As you can see, the two interpretations require the same amount of extra postulates above and beyond the wave function itself. Also, the MWI has to somehow define a formal notion of an observer/a classical world, which runs into questions of scale just as much as the measurement postulate of CI.
  - Joker_vD 3y ago
    > the MWI has to somehow define a formal notion of an observer/a classical world Yes: in MWI, those things don't exist. The world is quantum all the way up and all the way down, observers are simply (other) quantum system that get to interact with the quantum system under the consideration. An observation, then, is simply an interaction between two quantum systems and follows all the usual rules so instead of the wave-function collapse leaving you with the observed system in pure state X and the observer is in pure state Y, you get a huge superposition of "the observed system in pure state Xi, the observer is in pure state Yi" states in the end. Those substates, in a sense, are multiple worlds.
    - tsimionescu 3y ago
      You're missing the point I was highlighting. Quantum mechanics makes very specific, very precise predictions about the probabilities of an observer seeing any of those states, which we have confirmed are correct to extraordinary precision. The problem is explaining what is the relationship between these observed probabilities and the wave function amplitudes. If we say that all possible quantum states are realized in the universal wave function, we the need to explain why different states have different probabilities to an observer. The only way to do that in the deterministic world of MWI is to add a new postulate: one that says that for any state Xi, there are N observers in state Yi, where N = |psi(Xi)|, so that we can compute regular frequentist probabilities of an observer seeing a particular state over the amount of observers. This is perfectly reasonable, but it is just as much an extra postulate as the measurement postulate.
tauwauwau 3y ago
I watched it a long time ago. I just put it here because it presents the idea visually, not because I support or even understand it :)
consilient 3y ago
> In particular the many worlds interpretation makes no testable predictions, it's just a story. Yes, that's what "interpretation" means. If it made predictions that distinguished it from other interpretations, it would be a competing theory to quantum mechanics - and so far all such attempts have failed.
TillE 3y ago
The "popular science" takes on QM have generally been an enormous failure, focused on irrelevant fluff like this. I mean, I get it, it's a subject that you can't seriously understand without a degree in physics or chemistry. I had plenty of trouble with the math even at the undergrad level. But surely there's more interesting stories to tell of eg particle accelerator research, rather than fantasies.
- mrguyorama 3y ago
  More importantly, if you don't have 4 years worth of college math, quantum mechanics is EXTREMELY BORING from a layman's perspective. It's a bunch of extremely dense and specific math with very loaded concepts and terms and has no meaning to anyone who doesn't have a strong understanding of classical physics. "If you make a blackbody radiator nearly absolute zero, it should emit insanely high energy radiation based on our current empirical equations for radiated energy. This can only be fixed if energy can only be radiated in discrete sized packets, including a minimum size of packet" "Whats a black body radiator?" People don't understand quantum physics, its ramifications, or why that's interesting to physicists because people can't even be assed to do simple mental math at a grocery store to get themselves good deals before they go back to their algebra teacher and complain that they will never use math in real life